SEOUL -- A prominent animal shelter operator dubbed "the Queen of Rescue" faces a criminal investigation over revelations by a whistleblower that she has collected donations from sponsors by covering up active euthanasia for abandoned household pets with lethal drugs.

Animal and civic rights groups filed complaints with police or prosecutors on Friday, asking for an investigation into allegations that Park So-youn, president of the Coexistence of Animal Rights on Earth (CARE), has euthanized more than 200 homeless animals between 2015 and last year.

Along with fraud, embezzlement and the violation of an animal protection law, Park was also accused of funneling cash donations into personal use.

Park has been under fire since a former Care worker blew the whistle last month, accusing her of instructing her staff to euthanize animals. Care admitted to performing euthanasia selectively to some emaciated animals racked with pain, but activists insisted healthy animals have been put down for being furious or failing to be adopted for a long time.

Park's work to rescue dogs from being slaughtered at dog farms have been highly publicized. In July 2018, she was thrown into the spotlight for using Tori, the adopted pet dog of President Moon Jae-in, in a high-profile event in central Seoul to accelerate the adoption of abandoned dogs and oppose the consumption of dog meat.

Tori, a black homeless mongrel dog who was kept at an animal shelter after being rescued from a dog meat farm, has been adopted by Moon, an animal lover, to live together at his residence. Tori has become the symbol of a social campaign to accelerate the adoption of abandoned dogs and cats.